Compare indices instead of floats for probe actions

Marlin/Marlin.h

@@ -227,7 +227,8 @@ void enquecommands_P(const char *cmd); //put one or many ASCII commands at the e
 void prepare_arc_move(char isclockwise);
 void clamp_to_software_endstops(float target[3]);
 
-void refresh_cmd_timeout();
+extern unsigned long previous_millis_cmd;
+inline void refresh_cmd_timeout() { previous_millis_cmd = millis(); }
 
 #ifdef FAST_PWM_FAN
   void setPwmFrequency(uint8_t pin, int val);